Screen printing lives or dies by its separations. Every color gets its own screen, so the art has to be split into clean, printable layers before anything touches a press. A great design with sloppy separations means extra screens, registration fights, muddy prints and wasted shirts.
Here's a practical overview of how separations work and what to look for in separation-ready art.
Why Separations Matter
A screen printer doesn't print a picture. It prints a stack of individual colors, one screen at a time. Separations take a design and turn it into those layers. Good separations:
- Use as few screens as the design truly needs
- Register cleanly on press
- Account for the garment color
- Reproduce the customer's colors accurately
Spot Color Separations
Spot color is the most common approach for logos, text and graphic designs with solid colors. Each color in the design gets its own layer, printed with a mixed ink, often matched to a Pantone reference.
Spot color separations work best when the artwork is clean vector art. If the customer sends a low-resolution logo, the first step is usually a vector redraw. Redrawn art gives crisp edges at any print size and makes each color easy to isolate.
Tips for spot separations:
- Reduce the color count where it won't hurt the design. Every color is another screen.
- Label each layer with its ink color.
- Convert gradients to halftones the press can actually hold, or simplify them.
- Keep fine lines and small text thick enough to hold on the mesh you'll use.
Simulated Process Separations
Photographic or highly detailed artwork, especially on dark garments, often calls for simulated process separations. These use a limited set of spot inks with halftones to recreate a full-color look. They take more skill and more prep time than simple spot separations, and they need to be planned around the ink set, mesh counts and the garment.
Underbases
When printing on dark garments, light and bright inks need an underbase, usually white, printed first so the colors on top look bright and accurate. The underbase is its own separation, typically generated from the design and choked slightly so it doesn't peek out from behind the top colors.
Traps and Chokes
Even good presses have small registration variance. Traps (slight overlaps between adjacent colors) and chokes (pulling the underbase in slightly) hide that variance so you don't see gaps or edges of the wrong color. The right amount depends on your press and your process, so share your preferences with whoever prepares your separations.
Size the Art for the Print Location
A left-chest print, a full front and a sleeve print all have different size limits. Separations should be built at the actual print size for each location, not scaled on the fly, so line weights and halftones hold up.
Communicate With Your Separator
To get separations right the first time, share:
- Garment color(s)
- Ink colors or Pantone references
- Maximum number of screens
- Print size and location
- Any press preferences for traps, chokes and halftone settings
- Output format your film or computer-to-screen system needs
Outsourcing Separations
Separations are detailed, repetitive work that can eat hours of an art department's day. Outsourcing them lets your team focus on printing.
We prepare spot color separations with ink callouts, simulated process separations on request, underbases and traps, and vector redraws of low-resolution customer logos for screen printers and apparel shops. Vector redraws and color separations run $7 to $40. Start with one small redraw to check the quality before you commit. Every job includes two revision rounds, and we work white-label, so we never contact your customers unless you want us to.
Send over the next job your art department doesn't have time for.
Quick Separation Checklist
- Art is clean vector (or high-resolution for simulated process)
- Color count reduced to what the design truly needs
- Each layer named with its ink color or Pantone reference
- Underbase included and choked for dark garments
- Traps set to suit your press
- Fine lines and small text heavy enough to hold on the mesh
- Built at actual print size for each location
- Delivered in the format your film or screen system needs